Outcomes of modern total joint arthroplasty in patients with dementia: a systematic review of challenges and considerations for perioperative care

BACKGROUND: As the global prevalence of dementia rises, an increasing number of patients with cognitive impairment require Total Joint Arthroplasty (TJA). However, the specific impact of dementia on postoperative outcomes remains underreported. This systematic review evaluates the complications, mortality, and healthcare utilization associated with dementia in patients undergoing Total Hip (THA) and Total Knee Arthroplasty (TKA). METHODS: A systematic search of PubMed, Scopus, Web of Science, Embase, and the Cochrane Library was conducted following PRISMA guidelines. Eligible studies included comparative cohorts of patients with and without a diagnosis of dementia undergoing primary TJA. Methodological quality was appraised using the Newcastle-Ottawa Scale (NOS). Data were synthesized regarding mortality, readmissions, implant-related complications, and discharge disposition. RESULTS: Seven retrospective cohort studies comprising 13,816 patients with dementia and 869,061 controls were included. The mean NOS score was 8.4/9, indicating high methodological quality. Patients with dementia exhibited significantly worse outcomes across both procedures, including higher rates of postoperative delirium (OR: 4.25–6.40), mortality (HR: 1.43–3.05), and discharge to skilled nursing facilities (OR: 1.87). Stratification by procedure revealed distinct risk profiles: while both cohorts faced high readmission rates, THA patients demonstrated specific vulnerability to mechanical complications, including increased risks of dislocation, periprosthetic fracture (OR: 2.07), and revision surgery. These mechanical failures were frequently driven by falls and poor compliance with postoperative precautions rather than infection alone. CONCLUSION: Dementia is a robust independent predictor of adverse outcomes after TJA. While both THA and TKA carry elevated systemic risks, THA poses unique mechanical challenges that may warrant the use of high-stability implants (e.g., dual-mobility cups) to mitigate dislocation risks. Perioperative strategies should prioritize caregiver-led surveillance and strict fall prevention protocols to improve safety in this vulnerable population.